Certain 2-(substituted benzoyl)-5-(substituted or unsubstituted phenyl)-1,3-cyclohexanediones

ABSTRACT

Compounds of the formula ##STR1## wherein R is halogen; C 1  -C 2  alkyl; C 1  -C 2  alkoxy; trifluoromethoxy or difluoromethoxy; nitro; cyano; C 1  -C 2  haloalkyl; R a  SO n  -- wherein n is 0 or 2 and R a  is C 1  -C 2  alkyl, trifluoromethyl or difluoromethyl; 
     R 1  is hydrogen or C 1  -C 4  alkyl; 
     R 2  is hydrogen or C 1  -C 4  alkyl; or 
     R 1  and R 2  together are C 2  -C 5  alkylene; 
     R 3  is hydrogen or C 1  -C 4  alkyl; 
     R 4  is hydrogen or C 1  -C 4  alkyl; or 
     R 3  and R 4  together are C 2  -C 5  alkylene; 
     R 5 , R 6 , R 7  and R 8  independently are (1) hydrogen; (2) halogen; (3) C 1  -C 4  alkyl; (4) C 1  -C 4  alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C 1  -C 4  haloalkyl; (9) R b  SO n  -- wherein n is the integer 0, 1 or 2; and R b  is (a) C 1  -C 4  alkyl; (b) C 1  -C 4  alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR c  R d  and wherein R c  and R d  independently are hydrogen or C 1  -C 4  alkyl; (11) R e  C(O)-- wherein R e  is C 1  -C 4  alkyl or C 1  -C 4  alkoxy; or (12) --SO 2  NR c  R d  wherein R c  and R d  are as defined; and (13) --N(R c )C(O)R d  wherein R c  and R d  are as defined; and 
     R 9  is hydrogen or C 1  -C 4  alkyl, and their salts.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,350,705 relates to certain antihypertensive compoundsthat can have the following structural formula ##STR2## wherein R¹ isunsubstituted or substituted phenyl; M is --(CH₂)_(m) in which m is theinteger 0-4; and X, Y and Z are hydrogen, lower alkyl, lower alkoxy,lower alkylcarbonyloxy, hydroxy, lower alkylsulfonyl, nitro, cyano orhalogen. Specifically taught are2-benzoyl-5-phenyl-cyclohexane-1,3-dione and2-(4-chlorobenzoyl)-5-phenylcyclohexane-1,3-dione.

Description of the Invention

This invention relates to 2-(substituted benzoyl)-5-(substituted orunsubstituted phenyl)-1,3-cyclohexanediones and their use as herbicides.

One embodiment of this invention is an herbicidal composition comprisingan herbicidally active 2-(substituted benzoyl)-5-(substituted orunsubstituted phenyl)-1,3-cyclohexanedione and an inert carriertherefor. The 4- and 6-positions of the 1,3-cyclohexanedione moiety arepreferably substituted with groups hereinafter defined, most preferablywith hydrogen or methyl groups. The benzoyl moiety can be substituted,preferably with the groups hereinafter recited.

Also embodied within the scope of this invention are novel compoundshaving the following structural formula ##STR3## wherein R is halogen;C₁ -C₂ alkyl, preferably methyl; C₁ -C₂ alkoxy, preferably methoxy;trifluoromethoxy or difluoromethoxy; nitro; cyano; C₁ -C₂ haloalkyl,preferably trifluoromethyl; R^(a) SO_(n) --wherein n is 0 or 2,preferably 2 and R^(a) is C₁ -C₂ alkyl, preferably methyl,trifluoromethyl or difluoromethyl. Preferably, R is chlorine, bromine,C₁ -C₂ alkyl, C₁ -C₂ alkoxy, trifluoromethyl, cyano, nitro, C₁ -C₂alkylthio or C₁ -C₂ alkylsulfonyl; more preferably chlorine, nitro,methyl, trifluoromethyl or methylsulfonyl; and

R¹ is hydrogen or C₁ -C₄ alkyl, preferably methyl;

R² is hydrogen or C₁ -C₄ alkyl, preferably methyl; or

R¹ and R² together are C₂ -C₅ alkylene;

R³ is hydrogen or C₁ -C₄ alkyl, preferably methyl;

R⁴ is hydrogen or C₁ -C₄ alkyl, preferably methyl; or

R³ and R⁴ together are C₂ -C₅ alkylene;

R⁵, R⁶, R⁷ and R⁸ independently are (1) hydrogen; (2) halogen,preferably chlorine, fluorine or bromine; (3) C₁ -C₄ alkyl, preferablymethyl; (4) C₁ -C₄ alkoxy, preferably methoxy; (5) trifluoromethoxy; (6)cyano; (7) nitro; (8) C₁ -C₄ haloalkyl, more preferably trifluoromethyl;(9) R^(b) SO_(n) --wherein n is the integer 0, 1 or 2, preferably 2; and

R^(b) is

(a) C₁ -C₄ alkyl, preferably methyl;

(b) C₁ -C₄ alkyl substituted with halogen or cyano, preferablychloromethyl, trifluoromethyl or cyanomethyl;

(c) phenyl; or

(d) benzyl;

(10) --NR^(c) R^(d) wherein

R^(c) and R^(d) independently are hydrogen or C₁ -C₄ alkyl;

(11) R^(e) C(O)--wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy; (12)--SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined; or (13)--N(R^(c))C(O)R^(d) wherein R^(e) and R^(d) are as defined; and

R⁹ is hydrogen or C₁ -C₄ alkyl, preferably methyl, most preferablyhydrogen.

Preferably R⁵ is in the 3-position. More preferably R⁵ is hydrogen,chlorine, fluorine, trifluoromethyl, cyano, C₁ -C₄ alkoxy or C₁ -C₄thioalkyl. Most preferably, R⁵ is hydrogen. Preferably R⁶ is in the4-position. Most preferably R⁶ is halogen, cyano, trifluoromethyl, orR^(b) SO₂ wherein R^(b) is C₁ -C₄ alkyl, preferably methyl or C₁ -C₄haloalkyl, preferably chloromethyl, difluoromethyl or trifluoromethyl.Preferably R⁷ and R⁸ are hydrogen.

The term "C₁ -C₄ alkyl" includes methyl, ethyl, n-propyl, isopropyl,n-butyl, sec-butyl, isobutyl and t-butyl. The term "halogen" includeschlorine, bromine, iodine and fluorine. The terms "C₁ -C₄ alkoxy"includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy,isobutoxy and t-butoxy. The term "C₁ -C₄ haloalkyl" includes the alkylgroups defined above under C₁ -C₄ alkyl in which one or more hydrogensis replaced by chlorine, bromine, iodine or fluorine.

Salts of the above-described compounds (as defined hereinafter) areincluded within the scope of the instant invention.

The compounds of this invention can have the following four structuralformulae because of tautomerism: ##STR4## wherein R, R¹, R², R³, R⁴, R⁵,R⁶, R⁷, R⁸ and R⁹ are as defined above.

The circled proton on each of the four tautomers is reasonably labile.These protons are acidic and can be removed by reaction with a base toform a salt having an anion of the following four resonance forms:##STR5## wherein R, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are as definedabove.

Examples of cations of these bases are inorganic cations such as alkalimetals, e.g. lithium, sodium and potassium; the alkaline earth metals,e.g. calcium and magnesium or ammonium or organic cations such assubstituted ammonium, sulfonium, sulfoxonium or phosphonium wherein thesubstitutents are aliphatic or aromatic groups.

Those skilled in the art will recognize in considering the salts of thisinvention that varying degrees of associated between the anion andcation will exist depending upon the nature of the cation. In someinstances with a suitable cation, such as copper, the salt can exist ina chelated form.

The compounds of this invention and their salts are active herbicides ofa general type. That is, they are herbicidally effective against a widerange of plant species. The method of controlling undesirable vegetationof the present invention comprises applying an herbicidally effectiveamount of the above-described compounds or their salts to the area wherecontrol is desired.

The compounds of the present invention can be prepared by the followingtwo-step general method.

The process proceeds via the production of an enol ester intermediate asshown in reaction (1). The final product is obtained by rearrangement ofthe enol ester as shown in reaction (2).

The enol ester rearrangement is conducted in the presence of a catalyticamount of a source of cyanide anion and/or hydrogen cyanide, togetherwith a molar excess, with respect to the enol ester, or a moderate base.

The two reactions may be conducted as separate steps by isolation andrecovery of the enol ester using conventional techniques prior toconducting step (2), or by addition of a cyanide source to the reactionmedium after the formation of the enol ester, or in one step byinclusion of the cyanide source at the start of reaction (1). ##STR6##wherein R through R⁹ and moderate base are as defined and X is halogen,preferably chlorine, C₁ -C₄ alkyl-C(O)--O--, C₁ -C₄ alkoxy-C(O)--O-- or##STR7## wherein R, R⁵ and R⁶ in this portion of the molecule areidentical with those in the reactant shown above and the moderate baseis as defined, preferably tri-C₁ -C₆ alkylamine, alkali metal carbonateor alkali metal phosphate.

Generally, in step (1) mole amounts of the dione and substituted benzoylreactant are used, along with a mole amount or excess of the base. Thetwo reactants are combined in an organic solvent such as methylenechloride, toluene, ethyl acetate or dimethylformamide. The base orbenzoyl reactant preferably is added to the reaction mixture withcooling. The mixture is stirred at 0° C.-50° C. until the reaction issubstantially complete. ##STR8## wherein the moderate base and R throughR⁹ are as defined above.

Generally, in step (2) a mole of the enol ester intermediate is reactedwith 1 to 4 moles of the moderate base, preferably about 2 moles ofmoderate base and from 0.01 mole to about 0.5 mole or higher, preferablyabout 0.01-0.1 mole of the cyanide source. The mixture is stirred in areaction pot until the rearrangement is substantially complete at atemperature below 50° C., preferably about 20° C. to about 40° C., andthe desired product is recovered by conventional techniques.

The term "cyanide source" refers to a substance or substances whichunder the rearrangement conditions consists of or generates hydrogencyanide and/or cyanide anion.

Preferred cyanide sources are alkali metal cyanides such as sodium andpotassium cyanide; cyanohydrins of methyl alkyl ketones having from 1-4carbon atoms in the alkyl groups, such as acetone or methyl isobutylketone cyanohydrins; benzaldehyde cyanohydrin; cyanohydrins of C₂ -C₅aliphatic aldehydes such as acetaldehyde cyanohydrin, propionaldehydepropionaldehyde cyanohydrin, etc.; cyclohexanone cyanohydrin;lactonitrile; zinc cyanide; di- and tri-(lower alkyl) silyl cyanides,notably dimethyl- and trimethyl- silyl cyanide; potassium ferriccyanide; and hydrogen cyanide itself. Hydrogen cyanide is consideredmost advantageous as it produces relatively rapid reaction and isinexpensive. Among cyanohydrins the preferred cyanide source is acetonecyanohydrin.

The cyanide source is used in an amount up to about 50 mole percentbased on the enol ester. It may be used in as little as about 1 molepercent to produce an acceptable rate of reaction at about 40° C. on asmall scale. Larger scale reactions give more reproducible results withslightly higher catalyst levels of about 2 mole percent. Generally about1-10 mole % of the cyanide source is preferred.

The process is conducted with a molar excess, with respect to the enolester, of a moderate base. By the term "moderate base" is meant asubstance which acts as a base yet whose strength or activity as a baselies between that of strong bases such as hydroxides (which could causehydrolysis of the enol ester) and that of weak bases such asN,N-dimethylaniline (which would not function effectively). Moderatebases suitable for use in this embodiment include both organic bases,e.g., trialkylamines such as triethylamine and inorganic bases such asalkali metal carbonates and phosphates. Suitable inorganic bases includepotassium carbonate and trisodium phosphate.

The base is used in an amount of from about 1 to about 4 moles per moleof enol ester, preferably about 2 moles per mole.

When the cyanide source is an alkali metal cyanide, particularlypotassium cyanide, a phase transfer catalyst may be included in thereaction. Particularly suitable phase transfer catalysts are the crownethers.

A number of different solvents are useful in this process, depending onthe nature of the acid halide or the acylated product. A preferredsolvent for this reaction is 1,2-dichloroethane. Other solvents whichmay be employed, depending on the reactants or products include toluene,acetonitrile, methylene chloride, ethyl acetate, dimethylformamide, andmethyl isobutyl ketone (MIBK).

In general, depending on the nature of the reactants and the cyanidesource, the rearrangement may be conducted at temperatures up to about50° C.

The above described substituted benzoyl chlorides can be prepared fromthe corresponding substituted benzoic acids according to the teaching ofReagents for Organic Synthesis, Vol. I, L. F. Fieser and M. Fieser, pp.767-769 (1967). ##STR9## wherein R, R⁵ and R⁶ are as previously defined.

The substituted benzoic acids can be prepared by a wide variety ofgeneral methods according to the teaching of The Chemistry of CarboxylicAcids and Esters, S. Patai, editor, J. Wiley and Sons, New York, N.Y.(1969) and Survey of Organic Synthesis, C. A. Buehler and D. F. Pearson,J. Wiley and Sons, (1970).

The following are three representative examples of the methods describedtherein. ##STR10## wherein R, R⁵ and R⁶ are as previously defined.

In reaction (a) the substituted benzonitrile is heated to reflux inaqueous sulfuric acid for several hours. The mixture is cooled and thereaction product is isolated by conventional techniques. ##STR11##wherein R, R⁵ and R⁶ are as previously defined.

In reaction (b) the substituted acetophenone is heated to reflux forseveral hours in an aqueous hypochlorite solution. The mixture is cooledand the reaction product is isolated by conventional techniques.##STR12## wherein R, R⁵ and R⁶ are as previously defined.

In reaction (c) the substituted toluene is heated to reflux in anaqueous solution of potassium permanganate for several hours. Thesolution is then filtered and the reaction product is isolated byconventional techniques.

The substituted 1,3-cyclohexanediones can be prepared by a wide varietyof general methods according to the teachings of Modern SyntheticReactions, H. O. House, W. A. Benjamin, Inc., Menlo Park, Calif. (1972).

The following example teaches the synthesis of a representative compoundof this invention.

EXAMPLE 12-[2-Chloro-4-(methylsulfonyl)benzoyl]-4,4-dimethyl-5-phenyl-1,3-cyclohexanedione##STR13##

2-Chloro-4-(methylsulfonyl)benzoyl chloride (2.3 g, 9 mmol) and4,4-dimethyl-5-phenyl-1,3-cyclohexanedione (2.0 g, 9 mmol) weredissolved in 50 ml of acetonitrile. Triethylamine (1.8 g, 18 mmol) wasadded dropwise and the resulting solution was stirred at roomtemperature for 1 hour. Acetone cyanohydrin (0.17 g, 2 mmol) andtriethylamine (1.8 g, 18 mmol) were added and the reaction mixture wasstirred at room temperature for 1.5 hour. The reaction mixture wasconcentrated under vacuum and the residue dissolved in 100 ml ofmethylene chloride. The methylene chloride solution was washed with 2Nhydrochloric acid, 10% cupric acetate, water, 5% potassium carbonate, 2Nhydrochloric acid, and water. The methylene chloride solution was driedover anhydrous magnesium sulate and concentrated under vacuum, yielding1.2 g of the desired product as a viscous oil. It was identified as suchby nuclear magnetic resonance spectroscopy, infrared spectroscopy andmass spectroscopy.

The following is a table of certain selected compounds that arepreparable according to the procedure described hereto. Compound numbersare assigned to each compound and are used throughout the remainder ofthe application.

                                      TABLE I                                     __________________________________________________________________________     ##STR14##                                                                    Comp.                                                                         No. R  R.sup.1                                                                          R.sup.2                                                                          R.sup.3                                                                          R.sup.4                                                                          R.sup.5                                                                          R.sup.6                                                                             R.sup.7                                                                          R.sup.8                                                                          R.sup.9                                                                          m.p. °C.                          __________________________________________________________________________    1   Cl H  H  H  H  H  4-Cl  H  H  H  113-132                                  2   Br H  H  H  H  H  H     H  H  H  103-126                                  3   Cl H  H  H  H  3-Cl                                                                             4-Cl  H  H  H  123-134                                  .sup. 4.sup.a                                                                     Cl CH.sub.3                                                                         CH.sub.3                                                                         H  H  H  4-SO.sub.2 CH.sub.3                                                                 H  H  H  oil                                      5   NO.sub. 2                                                                        CH.sub.3                                                                         CH.sub.3                                                                         H  H  H  4-Cl  H  H  H  oil                                      6   NO.sub.2                                                                         H  H  H  H  H  4-Cl  H  H  H  wax                                      __________________________________________________________________________     .sup.a Prepared in Example 1.                                            

Herbicidal Screening Tests

As previously mentioned, the herein described compounds produced in theabove-described manner are phytotoxic compounds which are useful andvaluable in controlling various plant species. Selected compounds ofthis invention were tested as herbicides in the following manner.

Pre-emergence herbicide test: On the day preceding treatment, seeds ofseven different weed species are planted in loamy sand soil inindividual rows using one species per row across the width of a flat.The seeds used are green foxtail (FT) (Setaria viridis), watergrass (WG)(Echinochloa crusgalli), wild oat (WO) (Avena fatua), annularmorningglory (AMG) (Ipomoea lacunosa), velvetleaf (VL) (Abutilontheophrasti), Indian mustard (MD) (Brassica juncea), and yellow nutsedge(YNG) (Cyperus esculentus). Ample seeds are planted to give about 20 to40 seedlings per row, after emergence, depending upon the size of theplants.

Using an analytical balance, 600 milligrams (mg) of the compound to betested are weighed out on a piece of glassine weighing paper. The paperand compound are placed in a 60 milliliter (ml) wide-mouth clear bottleand dissolved in 45 ml of acetone or substituted solvent. Eighteen ml ofthis solution are transferred to a 60 ml wide-mouth clear bottle anddiluted with 22 ml of a water and acetone mixture (19:1) containingenough polyoxyethylene sorbitan monolaurate emulsifier to give a finalsolution of 0.5% (v/v). The solution is then sprayed on a seeded flat ona linear spray table calibrated to deliver 80 gallons per acre (748L/ha). The application rate is 4 lb/acre (4.48 Kg/ha).

After treatment, the flats are placed in the greenhouse at a temperatureof 70° to 80° F. and watered by sprinkling. Two weeks after treatment,the degree of injury or control is determined by comparison withuntreated check plants of the same age. The injury rating from 0 to 100%is recorded for each species as percent control with 0% representing noinjury and 100% representing complete control.

The results of the tests are shown in the following Table II.

                  TABLE II                                                        ______________________________________                                        Pre-Emergence Herbicidal Activity                                             Application Rate - 4.48 kg/ha                                                 Cmpd.                                                                         No.   FT     WG      WO    AMG   VL    MD    YNG                              ______________________________________                                        1      0     0       0     0     0     0     0                                2      0     0       0     0     0     0     0                                3      0     0       0     0     0     0     0                                4     100    100     100   100   100   100   80                               5      60    20      20    40    100   100   80                               6      90     90     80    10     90   90    80                               ______________________________________                                    

Post-Emergence Herbicide Test: This test is conducted in an identicalmanner to the testing procedure for the pre-emergence herbicide test,except the seeds of the seven different weed species are planted 10-12days before treatment. Also, watering of the treated flats is confinedto the soil surface and not to the foliage of the sprouted plants.

The results of the post-emergence herbicide test are reported in TableIII.

                  TABLE III                                                       ______________________________________                                        Post-Emergence Herbicidal Activity                                            Application Rate - 4.48 kg/ha                                                 Cmpd.                                                                         No.   FT     WG      WO    AMG   VL    MD    YNG                              ______________________________________                                        1     20     30       0    45    65    65    65                               2     45     75      30    20    90    40    65                               3     20     10       0     5    10    10     0                               4     80     80      60    80    80    80     0                               5      0      0       0    10    30    20     0                               6     80     50      60    60    80    80    60                               ______________________________________                                    

The compounds of the present invention and their salts are useful asherbicides and can be applied in a variety of ways at variousconcentrations. In practice, the compounds or salts are formulated intoherbicidal compositions, by admixture, in herbicidally effectiveamounts, with the adjuvants and carriers normally employed forfacilitating the dispersion of active ingredients for agriculturalapplications, recognizing the fact that the formulation and mode ofapplication of a toxicant may affect the activity of the materials in agiven application. Thus, these active herbicidal compounds or salts canbe formulated as granules of relatively large particle size, as wettablepowders, as emulsifiable concentrates, as powdery dusts, as flowables,as solutions or as any of several other known types of formulations,depending upon the desired mode of application. These formulations maycontain as little as about 0.5% to as much as about 95% or more byweight of active ingredient. A herbicidally effective amount dependsupon the nature of the seeds or plants to be controlled and the rate ofapplication varies from about 0.01 to approximately 10 pounds per acre,preferably from about 0.02 to about 4 pounds per acre.

Wettable powders are in the form of finely divided particles whichdisperse readily in water or other dispersants. The wettable powder isultimately applied to the soil either as a dry dust or as a dispersionin water or other liquid. Typical carriers for wettable powders includefuller's earth, kaolin clays, silicas and other readily wet organic orinorganic diluents. Wettable powders normally are prepared to containabout 5% to about 95% of the active ingredient and usually also containa small amount of wetting, dispersing, or emulsifying agent tofacilitate wetting and dispersion.

Emulsifiable concentrates are homogeneous liquid compositions which aredispersible in water or other dispersant, and may consist entirely ofthe active compound or salt with a liquid or solid emulsifying agent, ormay also contain a liquid carrier, such as xylene, heavy aromaticnaphthal, isophorone and other non-volatile organic solvents. Forherbicidal application, these concentrates are dispersed in water orother liquid carrier and normally applied as a spray to the area to betreated. The percentage by weight of the essential active ingredient mayvary according to the manner in which the composition is to be applied,but in general comprises about 0.5% to 95% of active ingredient byweight of the herbicidal composition.

Granular formulations wherein the toxicant is carried on relativelycoarse particles, are usually applied without dilution to the area inwhich suspension of vegetation is desired. Typical carriers for granularformulations include sand, fuller's earth, attapulgite clay, bentoniteclays, montmorillonite clay, vermiculite, perlite and other organic orinorganic materials which absorb or which may be coated with thetoxicant. Granular formulations normally are prepared to contain about5% to about 25% of active ingredients which may include surface-activeagents such heavy aromatic naphthas, kerosene or other petroleumfractions, or vegetable oils; and/or stickers such as destrins, glue orsynthetic resins.

Typical wetting, dispersing or emulsifying agents used in agriculturalformulations include, for example, the alkyl and aklylaryl sulfonatesand sulfates and their salts; polyhydric alcohols; polyethoxylatedalcohols; esters and fatty amines; and other types of surface-activeagents, many of which are available in commerce. The surface-activeagent, when used, normally comprises from 0.1% to 15% by weight of theherbicidal composition.

Dusts, which are free-flowing admixtures of the active ingredient withfinely divided solids such as talc, clays, flours and other organic andinorganic solids which act as dispersants and carriers for the toxicant,are useful formulations for soil-incorporating application.

Pastes, which are homogeneous suspensions of a finely divided solidtoxicant in a liquid carrier such as water or oil, are employed forspecific purposes. These formulations normally contain about 5% to about95% of active ingredient by weight, and may also contain small amountsof a wetting, dispersing or emulsifying agent to facilitate dispersion.For application, the pastes are normally diluted and applied as a sprayto the area to be affected.

Other useful formulations for herbicidal applications include simplesolutions of the active ingredient in a dispersant in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene and other organic solvents. Pressurizedsprays, typically aerosols, wherein the active ingredient is dispersedin finelydivided form as a result of vaporization of a low boilingdispersant solvent carrier, such as the Freons, may also be used.

The phytotoxic compositions of this invention can be applied to theplants in the conventional manner. Thus, the dust and liquidcompositions can be applied to the plant by the use of power-dusters,boom and hand sprayers and spray dusters. The compositions can also beapplied from airplanes as a dust or a spray or by rope wick applicationsbecause they are effective in very low dosages. In order to modify orcontrol growth of germinating seeds or emerging seedlings, as a typicalexample, the dust and liquid compositions can be applied to the soilaccording to conventional methods and can be distributed in the soil toa depth of at least 1/2 inch below the soil surface. It is not necessarythat the phytotoxic compositions be mechanically admixed with the soilparticles since these compositions can also be applied merely byspraying or sprinkling the surface of the soil. The phytotoxiccompositions of this invention can also be applied by addition toirrigation water supplied to the field to be treated. This method ofapplication permits the penetration of the compositions into the soil asthe water is absorbed therein. Dust compositions, granular compositionsor liquid formulations applied to the surface of the soil can bedistributed below the surface of the soil by conventional means such asdiscing, dragging or mixing operations. In the following examples theherbicidal compound can be substituted with the herbicidal salt of thecompound.

    ______________________________________                                        General Formula with Ranges                                                                    Specific Formula                                             ______________________________________                                        EMULSIFIABLE CONCENTRATE FORMULATIONS                                         Herbicidal compound                                                                         5-55   herbicidal compound                                                                           24                                       surfactant(s)                                                                               5-25   proprietary blend of oil-                                                                     10                                       solvent(s)   20-90   soluble sulfonates and                                                100%    polyoxyethylene ethers                                                        polar solvent   27                                                            petroleum hydrocarbon                                                                         39                                                                            100%                                     WETTABLLE POWDER FORMULATIONS                                                 herbicidal compound                                                                         3-90   herbicidal compound                                                                           80                                       wetting agent                                                                              0.5-2   sodium dialkyl naph-                                                                          0.5                                                           thalene                                                  dispersing agent                                                                           1-8     sulfonate                                                diluent(s)   8.5-87  sodium lignosulfonate                                                                         7                                                     100%    attapulgite clay                                                                              12.5                                                                          100%                                     EXTRUDED GRANULAR FORMULATIONS                                                herbicidal compound                                                                         1-20   herbicidal compound                                                                           10                                       binding agent                                                                               0-10   lignin sulfonate                                                                              5                                        diluent(s)   70-99   calcium carbonate                                                                             85                                                    100%                    100%                                     FLOWABLE FORMULATIONS                                                         herbicidal compound                                                                        20-70   herbicidal compound                                                                           45                                       surfactant(s)                                                                               1-10   polyoxyethylene ether                                                                         5                                        suspending agent(s)                                                                        0.05-1  attagel         0.05                                     antifreeze agent                                                                            1-10   propylene glycol                                                                              10                                       antimicrobial agent                                                                         1-10   1,2 benzisothiazoline-                                                                        0.03                                                          3-one                                                    antifoam agent                                                                             0.1-1   silicone defoamer                                                                             0.02                                     solvent      7.95-   water           39.9                                                  77.85                   100%                                                  100%                                                             ______________________________________                                    

When salts are used as the active ingredient in the herbicidalcompositions of this invention it is recommended to use salts that areagriculturally acceptable.

The phytotoxic compositions of this invention can also contain otheradditives, for example, fertilizers, other herbicides and otherpesticides, used as adjuvant or in combination with any of theabovedescribed adjuvants. Fertilizers useful in combination with theactive ingredients include, for example, ammonium nitrate, urea andsuperphosphate.

What is claimed is:
 1. Compounds of the formula ##STR15## wherein R ishalogen; C₁ -C₂ alkyl; C₁ -C₂ alkoxy; trifluoromethoxy ordifluoromethoxy; nitro; cyano; C₁ -C₂ haloalkyl; R^(a) SO_(n) -- whereinn is 0 or 2 and R^(a) is C₁ -C₂ alkyl, trifluoromethyl ordifluoromethyl;R¹ is C₁ -C₄ alkyl; R² is hydrogen or C₁ -C₄ alkyl; or R¹and R² together are C₂ -C₅ alkylene; R³ is hydrogen or C₁ -C₄ alkyl; R⁴is hydrogen or C₁ -C₄ alkyl; or R³ and R⁴ together are C₂ -C₅ alkylene;R⁵, R⁶, R⁷ and R⁸ independently are (1) hydrogen; (2) halogen; (3) C₁-C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6) cyano; (7)nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n is theinteger 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkylsubstituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10)--NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogen or C₁-C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄alkoxy; or (12) --SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are asdefined; and (13) --N(R^(c))C(O)R^(d) wherein R^(c) and R^(d) are asdefined; and R⁹ is hydrogen or C₁ -C₄ alkyl, and their salts.
 2. Thecompounds of claim 1 wherein R is chlorine, bromine, methyl, methoxy,nitro, trifluoromethyl or methylsulfonyl; R¹ is methyl, R², R³ and R⁴are hydrogen or methyl; R⁵ and R⁶ independently are (1) hydrogen; (2)halogen; (3) C₁ -C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6)cyano; (7) nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n isthe integer 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkylsubstituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10)--NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogen or C₁-C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄alkoxy; or (12) SO2NRcRd wherein R^(c) and R^(d) are as defined; or (13)--N--(R^(c))C--(O)R^(d) wherein R^(c) and R^(d) are as defined; R⁷ ishydrogen; R⁸ is hydrogen; and R⁹ is hydrogen.
 3. The compounds of claim2 wherein R⁵ and R⁶ are independently are hydrogen; chlorine; fluorine;bromine; methyl; C₁ -C₄ alkoxy; trifluoromethoxy; cyano; nitro;trifluoromethyl; R^(b) SO_(n) -- wherein n is the integer 0 or 2 andR^(b) is methyl, chloromethyl, trifluoromethyl; ethyl or n-propyl, R^(e)C(O)-- where R^(e) is C₁ -C₄ alkyl; or SO₂ NR^(c) R^(d) wherein R^(c)and R^(d) are as defined, and R⁵ is in the 3-position and R⁶ is in the4-position.
 4. The compounds of claim 2 wherein R⁵ is hydrogen and R⁶ ishydrogen, chlorine, bromine, fluorine, cyano, trifluoromethyl or R^(b)SO₂ wherein R^(b) is C₁ -C₄ alkyl or C₁ -C₄ haloalkyl.
 5. The compoundof claim 2 wherein R is chlorine; R¹ is methyl; R² is methyl; R³ ishydrogen; R⁴ is hydrogen; R⁵ is hydrogen; R⁶ is 4-SO₂ CH₃ ; R⁷ ishydrogen; R⁸ is hydrogen; and R⁹ is hydrogen.
 6. The compound of claim 2wherein R is nitro; R¹ is methyl; R² is methyl; R³ is hydrogen; R⁴ ishydrogen; R⁵ is hydrogen; R⁶ is 4-chlorine; R⁷ is hydrogen; R⁸ ishydrogen; and R⁹ is hydrogen.
 7. A herbicidal composition comprising anherbicidally active 2-benzoyl-5-phenyl-1,3-cyclohexanedione compound ofthe formula ##STR16## wherein R is halogen; C₁ -C₂ alkyl; C₁ -C₂ alkoxy;trifluoromethoxy of difluoromethoxy; nitro; cyano; C₁ -C₂ haloalkyl;R^(a) SO_(n) -- wherein n is 0 or 2 and R^(a) is C₁ -C₂ alkyl,trifluoromethyl or difluoromethyl;R¹ is C₁ -C₄ alkyl; R² is hydrogen orC₁ -C₄ alkyl; or R¹ and R² together are C₂ -C₅ alkylene; R³ is hydrogenor C₁ -C₄ alkyl; R⁴ is hydrogen or C₁ -C₄ alkyl; or R³ and R⁴ togetherare C₂ -C₅ alkylene; R⁵, R⁶, R⁷ and R⁸ independently are (1) hydrogen;(2) halogen; (3) C₁ -C₄ alkyl; (4) C₁ -C₄ alkoxy; (5) trifluoromethoxy;(6) cyano; (7) nitro; (8) C₁ -C₄ haloalkyl; (9) R^(b) SO_(n) -- whereinn is the integer 0, 1 or 2; and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10)-NR^(c) R^(d) wherein R^(c) and R^(d) independently are hydrogen or C₁-C₄ alkyl; (11) R^(e) C(O)-- wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄alkoxy; or (12) --SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are asdefined; and (13) --N(R^(c))C(O)R^(d) wherein R^(c) and R^(d) are asdefined; and R⁹ is hydrogen or C₁ -C₄ alkyl, and their salts and aninert carrier therefor.
 8. The composition of claim 7 wherein R ischlorine, bromine, methyl, methoxy, nitro, trifluoromethyl ormethylsulfonyl; R¹ is methyl, R², R³ and R⁴ are hydrogen or methyl; R⁵and R⁶ independently are (1) hydrogen; (2) halogen; (3) C₁ -C₄ alkyl;(4) C₁ -C₄ alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C₁-C₄ haloalkyl; (9) R^(b) SO_(n) -- wherein n is the integer 0, 1 or 2;and R^(b) is (a) C₁ -C₄ alkyl; (b) C₁ -C₄ alkyl substituted with halogenor cyano; (c) phenyl; or (d) benzyl; (10) --NR^(c) R^(d) wherein R^(c)and R^(d) independently are hydrogen or C₁ -C₄ alkyl; (11) R^(e) C(O)--wherein R^(e) is C₁ -C₄ alkyl or C₁ -C₄ alkoxy; or (12) SO₂ NR^(c) R^(d)wherein R^(c) and R^(d) are as defined; or (13) --N--(R^(c))C--(O)R^(d)wherein R^(c) and R^(d) are as defined; R⁷ is hydrogen; R⁸ is hydrogen;and R⁹ is hydrogen.
 9. The composition of claim 8 wherein R⁵ and R⁶ areindependently are hydrogen; chlorine; fluorine; bromine; methyl; C₁ -C₄alkoxy; trifluoromethoxy; cyano; nitro; trifluoromethyl; R^(b) SO_(n) --wherein n is the integer 0 or 2 and R⁶ is methyl, chloromethyl,trifluoromethyl, ethyl, or n-propyl; R^(e) C(O)-- where R^(e) is C₁ -C₄alkyl; or SO₂ NR^(c) R^(d) wherein R^(c) and R^(d) are as defined, andR⁵ is in the 3-position and R⁶ is in the 4-position.
 10. The compositionof claim 8 wherein R⁵ is hydrogen and R⁶ is hydrogen, chlorine, bromine,fluorine, cyano, trifluoromethyl or R^(b) SO₂ wherein R^(b) is C₁ -C₄alkyl or C₁ -C₄ haloalkyl.
 11. The composition of claim 8 wherein R ischlorine; R¹ is methyl; R² is methyl; R³ is hydrogen; R⁴ is hydrogen; R⁵is hydrogen; R⁶ is 4-SO₂ CH₃ ; R⁷ is hydrogen; R⁸ is hydrogen; and R⁹ ishydrogen.
 12. The composition of claim 8 wherein R is nitro; R¹ ishydrogen; R² is methyl; R³ is hydrogen; R⁴ is hydrogen; R⁵ is hydrogen;R⁶ is 4-chlorine; R⁷ is hydrogen; R⁸ is hydrogen; and R⁹ is hydrogen.